HELP - Sick Turbastrea Sun Coral!

[SFMAquariums]

Hello,

I have a beautiful Turbastrea sun coral colony that was one of the first additions to my ~225 gallon mixed reef tank. My tank has been running for 6-7 months now.

It appeared to be doing fantastic at first & we were target feeding it with mysis daily. For the last few days, the polyps have not been opening like they usually do & I haven’t been able to target feed it. Yesterday, I noticed that one of the polyps on the back/side of the colony seemed to be retracting & exposing the skeleton. I therefore took the coral out to perform a coral dip & realized that the backside of the coral (hidden from view) has more polyp retraction than I realized with exposed skeleton, but has also developed a black matt that is kinda soft/spongy to the touch.

I did some research & based off that, completed the coral dip. I then tried to gently scrub away some of the black matt with a soft bristle toothbrush but there was no noticeable effect. I took some pictures & returned the coral to my tank. I checked a few hours later & this morning - polyps have remained mostly closed.

I’m worried that it has developed some type of infection secondary to either improper water parameters or (more likely) cold shock - preceding all of this (1-2 weeks ago), my partner tried to do a water change & accidentally dropped the water temperature suddenly. After this we lost our decorator crab & an urchin, which then led to some parameter spikes in phosphate/nitrates which we have been trying to manage. My theory being that either the cold shock/parameter change caused death of some of the coral tissue on the back of the colony that I didn’t notice & that tissue has now become infected.

Does this seem reasonable? Does anybody have other theories? Any recommendations for next steps in terms of treatment?

Any advice would be greatly appreciated. It’s been a rough few weeks in our tank - losing our favourite decorator crab & another urchin. This is one of our favourite corals & we would hate to lose it.

 

[vetteguy53081]

Hello,

I have a beautiful Turbastrea sun coral colony that was one of the first additions to my ~225 gallon mixed reef tank. My tank has been running for 6-7 months now.

It appeared to be doing fantastic at first & we were target feeding it with mysis daily. For the last few days, the polyps have not been opening like they usually do & I haven’t been able to target feed it. Yesterday, I noticed that one of the polyps on the back/side of the colony seemed to be retracting & exposing the skeleton. I therefore took the coral out to perform a coral dip & realized that the backside of the coral (hidden from view) has more polyp retraction than I realized with exposed skeleton, but has also developed a black matt that is kinda soft/spongy to the touch.

I did some research & based off that, completed the coral dip. I then tried to gently scrub away some of the black matt with a soft bristle toothbrush but there was no noticeable effect. I took some pictures & returned the coral to my tank. I checked a few hours later & this morning - polyps have remained mostly closed.

I’m worried that it has developed some type of infection secondary to either improper water parameters or (more likely) cold shock - preceding all of this (1-2 weeks ago), my partner tried to do a water change & accidentally dropped the water temperature suddenly. After this we lost our decorator crab & an urchin, which then led to some parameter spikes in phosphate/nitrates which we have been trying to manage. My theory being that either the cold shock/parameter change caused death of some of the coral tissue on the back of the colony that I didn’t notice & that tissue has now become infected.

Does this seem reasonable? Does anybody have other theories? Any recommendations for next steps in terms of treatment?

Any advice would be greatly appreciated. It’s been a rough few weeks in our tank - losing our favourite decorator crab & another urchin. This is one of our favourite corals & we would hate to lose it.

May be getting too much light and/or flow. These specimens do best in very low light and low flow and best fed at night as you will see them open up at night, ready to feed

 

[SFMAquariums]

May be getting too much light and/or flow. These specimens do best in very low light and low flow and best fed at night as you will see them open up at night, ready to feed

I don’t think too much light is the issue - I have 2 RedSea G2 115 which is honestly probably a bit weak for a tank my size in terms of lighting. The coral has always been located on the sandbed.

In terms of flow, I had read that you ideally want low to moderate indirect flow. Its in the middle of my tank so not directly near any of my pumps & I have it tucked behind a larger rock to shield it from direct flow but maybe I should try moving it do a different location.

I would just find it a bit weird to be a flow/light issue when neither of those factors have changed since I got the coral & it seemed to be doing really well until now!

 

[vetteguy53081]

I don’t think too much light is the issue - I have 2 RedSea G2 115 which is honestly probably a bit weak for a tank my size in terms of lighting. The coral has always been located on the sandbed.

In terms of flow, I had read that you ideally want low to moderate indirect flow. Its in the middle of my tank so not directly near any of my pumps & I have it tucked behind a larger rock to shield it from direct flow but maybe I should try moving it do a different location.

I would just find it a bit weird to be a flow/light issue when neither of those factors have changed since I got the coral & it seemed to be doing really well until now!

Check your phosphate and nitrate level . Also assure calcium not below 400